1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to synchronizing a reproduction time of a time-shifted content with a reproduction time of a real-time content, and more particularly, to performing a process of refining a recorded content such that a reproduction time of a content recorded using a time-shift function is synchronized with a reproduction time of a real-time content.
2. Description of the Related Art
A Personal Video Recorder (PVR) system is a personal digital video recorder that stores digital broadcasting contents in a nonvolatile memory, such as a hard disk drive (HDD) and so on, converts satellite broadcasting contents into digital signals and stores the converted digital signals, and outputs and reproduces the contents on a monitor, such as a television (TV), as needed. Unlike video cassette recorders (VCRs) which store image signals in a magnetic tape, the PVR system is a novel digital recorder that stores information in a hard disk and reproduces the information. That is, the PVR can record broadcasting programs corresponding to a predetermined time using the internal hard disk drive of the set-top box or main body of a (TV). At this time, data is stored in the HDD after being encoded in an Moving Picture Experts Group (MPEG)-2 system and the stored data is output after being decoded in the MPEG-2 system for reproduction.
That is, the PVR system converts digital broadcasting data (Europe: DVB, Korea/Japan/North America: ATSC) or analog broadcasting data (Europe: PAL, Korea/Japan/North America: NTSC) received through a broadcasting channel of a TV system into digital signals using a central processing unit (CPU) and a video signal processor. Then, the PVR system converts the digital signals into digital signal data and stores the converted digital signal data in an internal memory (HDD) of the system, performs analog-to-digital (A/D) conversion of the stored digital signal data, and reproduces the A/D converted data on a display device or a screen at a desired time according to a desired method selected by a viewer.
FIG. 1 is a block diagram illustrating a PVR system according to the related art.
As shown in FIG. 1, the PVR system includes a tuner/demodulator 10 which selects a desired channel and converts selected digital broadcasting signals into transport streams (TS), a demultiplexer 20 which divides the transport streams converted by the tuner/demodulator 10 into images, sound, and data, an HDD 40 which stores the images, sound, and data streams, a CPU 30 which controls storage of the divided images in the HDD 40, and an MPEG2 decoder 50 which decodes the data streams received from the tuner/demodulator 10 or the data streams stored in the HDD 40 into images and sound, and processes the data streams to be output through a screen and a speaker.
The PVR system has a broadcasting program reserving/recording function and a time-shift function. Here, the time-shift function stores stream buffers of a broadcasting program received through the tuner 10 in a storage medium and allows a viewer to arbitrarily watch a desired part of the stored broadcasting program data after a predetermined time elapses. If a time-shift mode starts, real-time contents (that is, live broadcasting data) are not displayed on a screen but instead are stored in the storage medium. An image displayed on the actual screen is the broadcast recorded by the PVR before a current time.
When the time-shift function is activated, there may be a time difference between a broadcast to be received by a viewer and a broadcast to be actually received. However, the viewer sometimes wants to watch a live broadcast after performing the time-shift mode.
In the above-described case, a current PVR system stops to decode the stored data and decodes broadcasting data from the tuner. At this moment, some broadcasting data cannot be seen by, the viewer because broadcasting data skips by the amount according to the time difference.
Accordingly, there is a problem in that the viewer should rapidly rewind the recorded broadcasting contents or continue to watch the recorded contents using the time-shift function.
Korean Unexamined Patent Application Publication No. 2005-0050456 discloses a digital broadcasting contents recording and reproducing apparatus for time-shift reproduction without time delay including a buffer and a reproduction control unit. Here, when a time-shift reproduction selection signal is received from the outside, the reproduction control unit controls at least a part of contents stored in a recording medium to output to the buffer. Then, when a time-shift reproduction start signal is received from the outside, the reproduction control unit controls such that the part of contents stored in the buffer starts to be reproduced. According to this apparatus, transport streams can be encoded and decoded before the part of contents are stored in the buffer, such that a time delay is minimized during the time-shift reproduction. Therefore, corresponding contents can be rapidly reproduced when a viewer requests the time-shift reproduction. However, the above-described document does not disclose a technique for synchronizing a reproduction time of the time-shifted content (that is, recorded broadcasting contents) with a reproduction time of a real-time content.